Decentralizing Core Network Functionalities

ABSTRACT

The present invention relates to methods and apparatuses for providing network access, wherein a connection to a core network is established via a wireless access device ( 20 ) and a gateway device ( 42 ). Connectivity of the wireless access device ( 20 ) is restricted to a pre-defined group of core network address of a pool of gateway devices ( 42 ) with multi-node connectivity to the core network, and a single address is selected to establish the connection to a one of the gateway devices ( 42 ). The gateway device ( 42 ) is provided with a relay function for mapping a single input address to a plurality of core network addresses based on a location information of the wireless access device ( 10 ) and with at least one co-located decentralized core network functionality.

CROSS REFERENCE TO RELATED APPLICATION

This is a continuation of copending application Ser. No. 12/989,861filed Feb. 28, 2011, which is a national stage application ofInternational Application No. PCT/EP2009/003085 filed Apr. 28, 2009,which are hereby incorporated by reference in their entireties.

FIELD OF THE INVENTION

The present invention relates to methods and apparatuses for networkaccess to a wireless network, such as—but not limited to—UniversalMobile Communication System (UMTS) or Long Term Evolution (LTE)networks.

BACKGROUND OF THE INVENTION

Home base stations, home NodeBs, femto eNodeBs or any other type of homeaccess device (in the following referred to as “HeNB”) have become awidely discussed topic within 3^(rd) Generation Partnership Project(3GPP) as well as in the operator and manufacturer community. Whendeployed in homes and offices, HeNBs allow subscribers to use theirexisting handsets—in a building—with significantly improved coverage andincreased broadband wireless performance. Moreover, Internet Protocol(IP) based architecture allows deployment and management in virtuallyany environment with broadband Internet service.

With the introduction of High Speed Downlink Packet Access (HSDPA) invarious commercial networks, operators noticed quite substantial daterate, i.e. capacity, consumption of single users. Those are in mostcases users staying at home and using a HSDPA data card or the like forsubstantial Internet surfing like downloading movies etc. However,existing mobile communication systems (e.g. Global System for Mobilecommunications (GSM), Wideband Code Division Multiple Access(WCDMA/HSDPA) are not optimal suited for such home-based application, asthose were developed and defined under the assumption of coordinatednetwork deployment, whereas HeNBs are typically associated withuncoordinated and large scale deployment.

In HeNB scenarios, it is generally assumed that an end user is buying acheap (Wireless Local Area Network (WLAN) like) product and alsoinstalls this physical entity at his home. Such a HeNB would thenprovide coverage/service to the terminals registered by the owner of theHeNB. Still the HeNB would use the same spectrum owned by the operatorand as such at least partly the spectrum the operator is using toprovide macro cell coverage to the area where the HeNB is located in.

Moreover, sharing and pooling properties of the core network, whereseveral operator's core networks are attached to the same access node orforeign mobile terminal devices or user equipments (UEs) roam into aHeNB nominally “owned” by a certain operator, should be hidden to theHeNB, in order to ease handling of the HeNB. In general, conventionalaccess devices, such as NodeBs or eNodeBs, being function-wise similarto HeNBs, bear a lot of nodal functions which are not necessary forsimple home operation.

It has recently emerged that operators are interested in a so calledlocal break-out (LBO) of “bulk” traffic. LBO is to be understood as adelivery of Internet traffic (or other bulk traffic) in a way that itdoes not transit across the operator's EPC, i.e. the Internet trafficwould be forwarded to and received from the Internet via a gateway localto the base station without having to transit through the operator'score network nodes. LBO could also apply to voice traffic between twouser equipments (UEs) in the same local area service area, where a localarea service is a region in which local services adopting LBO can bedeployed.

The deployment of HeNBs in LTE will have a strong impact on scalabilityat the EPC due to the very large deployment scale and therefore highnumbers of interfaces to be established between HeNBs and EPC. Also,such deployment will cause an increase in the cost of operation andmaintenance (O&M) operations as the O&M network will have to providemonitoring and control of all HeNBs.

However, current LTE standard specifications allow traffic breakouttowards the public IP network only via a so called Public Domain NetworkGateway (PDN GW). This configuration does not allow to offload trafficrelative to Internet services from the centralized EPC, puttingconstraints on the EPC capacity and causing an increase of cost per bitof information traveling across the EPC.

SUMMARY

It is an object of the present invention to enable LBO of bulk trafficin wireless access network architectures.

This object is achieved by a method of providing network access, saidmethod comprising:

-   -   establishing a connection to a core network via a wireless        access device;    -   restricting connectivity of said wireless access device to a        pre-defined group of core network address of a pool of gateway        devices with multi-node connectivity to said core network; and    -   selecting a single address to establish said connection to one        of said gateway devices.

Furthermore, the above object is achieved by a method of providingnetwork access, said method comprising:

-   -   using a gateway device for establishing a connection from a        wireless access device to a core network;    -   providing said gateway device with a relay function for mapping        a single input address to a plurality of core network addresses        based on a location information of said wireless access device;        and    -   decentralizing at least one core network functionality and        co-locating it with said gateway device.

Additionally, the above object is achieved by an apparatus for providingaccess to a core network, said apparatus comprising:

-   -   connecting means which provide a connectivity restricted to a        pre-defined group of core network address of a pool of gateway        devices with multi-node connectivity to said core network; and    -   selecting means for selecting a single address from said group        of core network addresses to establish a connection to a one of        said gateway devices.

Finally, the above object is achieved by an apparatus for establishing aconnection from a wireless access device to a core network, comprising:

-   -   relay means for mapping a single input address to a plurality of        core network addresses based on a location information of said        wireless access device; and    -   at least one co-located decentralized core network        functionality.

Accordingly, two deployment concepts of gateway device and decentralizedcore network functionality (enabling e.g. LBO) are linked and solutionsare proposed for scenarios in which the gateway device and the corenetwork functionality (e.g. the LBO gateway or gateway function) can bejoint together in or at the same node.

A clear advantage of the proposed solution is that it allows localbreakout of bulk Internet traffic at a point local to the wirelessaccess devices, i.e. it allows Internet traffic not to be routed throughthe central core network, hence reducing the cost per bit of informationdelivered to/from the user. This differentiation of “bulk traffic”enables local peer-to-peer routing and optimized user data routing topacket data networks (e.g. the Internet) without passing centralizedcellular gateways on the core network. Now, local traffic can be keptwithin the local area and also operator's core networks becomeoff-loaded from bulk traffic that is out of quality of service (QoS)control and charging (due to an applied flat rate).

The proposed pool of gateway devices provides the additional advantagethat the load can be distributed more homogeneously across a predefinedpool of neighbour gateway devices, e.g., across secondary gateways.Thereby, single point of failure problems concerning failures of gatewaydevices (independently of the core network functionalities collocatedwith it) can be overcome.

Due to restricted single-node connectivity of the wireless access device(e.g. HeNB), multi-node functionalities, like network node selectionfunction (NNSF) and multi-core-network-node connectivity, can be removedfrom and completely located outside the wireless access network. Theycan be centralized at the gateway node between the wireless accessnetwork and the core network, e.g. an evolved packet core (EPC).Thereby, access device functions (e.g. LTE eNB S1 functions and thelike) can be simplified.

The proposed incorporation of core network functionalities in thegateway device thus allows LBO without forcing the “bulk” Internettraffic to flow through the core network. Moreover, the problem ofgateway recovery in cases where such node is also used for LBO can besolved.

Moreover, efforts in manufacturing, deployment, configuration, operationand maintenance of the wireless access devices can be reduced. Providingparts of the access node functions in a network equipment external tothe wireless access node circumvents complexity of all mentionedaspects. Furthermore, in mass deployment, this is advantageous due tolower production costs, lower operational costs and simpler handling ofconnectivity towards the core network.

Traffic exchanged by terminal devices served within the gateway domaincan be routed without involving the central core network, i.e. U-Planetraffic routes within a gateway domain will go from one peer terminaldevice to the other peer terminal device passing through the gatewaydevice.

This allows to reduce the complexity of the gateway device, which isimportant due to the relatively high number of gateway devices operatorsmay have to deploy if very high volumes of wireless access devices needto be achieved.

A user-plane connection may be established to the gateway device via asingle Internet Protocol address. Additionally, a control-planeconnection may be established to the gateway device via a singletransmission protocol association containing a single transmissionprotocol stream and a single Internet Protocol address. The cell of thewireless access device may be established as a closed subscriber groupcell identified by a tracking area identifier.

The gateway device may provide connections to the core network viaseveral Internet Protocol addresses and several transmission protocolstreams. An automatic setup of the gateway device with a pre-definedidentification. The predefined identification may comprise a trackingarea with at least one dedicated tracking area code.

According to first options, the at least one core network functionalitymay comprises at least one of a serving gateway functionality, a packetdata network gateway functionality, a mobility management functionality,so that at least one of a user plane and a control plane of saidconnection is terminated at said gateway device. As a specific example,the mobility management functionality may be part of a pool of mobilitymanagement entities local to the gateway device. According to anotherexample, a default bearer may be provided for traffic terminated at saidgateway device.

This enables a more synchronised and easy to manage procedure for bearermonitoring and control and U-Plane traffic mapping into radio bearers.Obviously, more functions will need to be supported by the HeNB GW.

The proposed at least one core network functionality may be used toprovide local routing without passing a centralized gateway device atthe core network. In a specific example, the local routing may compriseat least one of local peer-to-peer routing and local routing to anexternal packet data network (e.g. the Internet). In this way LBO forInternet traffic could happen at the HeNB GW without forcing collocationof an S-GW in it. This would make the HeNB GW more cost effective, stillimproving the cost per bit of information travelling across thecentralized EPC.

According to a second option, the at least one core networkfunctionality may comprise a control plane anchor function for thewireless access device, so that the user plane of the connection isterminated at said wireless access device.

In this way there is no need to place the Operator owned HeNB GW in theprivate premises without impacting the possibility for the operator tomanage HeNBs and fully control the consumed LBO services. Also the LBOtraffic on the U-plane is kept within the local intranet e.g. safelybehind the firewall.

Other advantageous modifications are defined in the dependent claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described in greater detail based onembodiments with reference to the accompanying drawings in which:

FIG. 1 shows a schematic network architecture with a HeNB gatewaysupport;

FIG. 2 shows a schematic block diagram of a HeNB and a HeNB gatewayaccording to various embodiments

FIG. 3 shows a schematic network architecture with a HeNB gatewaysupport incorporating several gateway functionalities according to afirst embodiment;

FIG. 4 shows a schematic network architecture with a HeNB gatewaysupport incorporating several gateway functionalities according to asecond embodiment;

FIG. 5 shows a schematic network architecture with a HeNB gatewaysupport incorporating a single PDN gateway functionality according to athird embodiment;

FIG. 6 shows a schematic network architecture with a HeNB gatewaysupport incorporating a C plane anchor functionality according to afourth embodiment;

FIG. 7 shows a schematic processing and signaling diagram of a HeNBgateway reselection procedure according to a fifth embodiment; and

FIG. 8 shows a schematic block diagram of software-based implementationaccording to a sixth embodiment.

DESCRIPTION OF THE EMBODIMENTS

In the following, embodiments of the present invention will be describedbased on exemplary and non-limiting LTE network architectures.

FIG. 1 shows a schematic network architecture with a HeNB gateway in anon-network sharing case according to a first embodiment.

According to FIG. 1, a Home eNodeBs (HeNB) 20 with reduced functionalityis provided in a subscriber home environment, e.g. within a building, toprovide wireless access for a user equipment (UE) 10, and is connectedto a HeNB gateway (node) 40. The HeNB gateway 40 provides connection viaan S1-MME reference point to a mobility management entity (MME) 50 or apool thereof and via an S1-U reference point to a signaling gateway(S-GW) 60 or a pool thereof. Both MME 50 and S-GW 60 provide connectionsto a macro eNB 30 which serves a macro cell in or under which the HeNB20 located. The protocol over the S1-MME reference point can be enhancedRadio Access Network Application (eRANAP) and may use Stream ControlTransmission Protocol (SCTP) as the transport protocol. The S1-Ureference point can be used for per-bearer user plane tunneling andinter-eNB path switching during handover. The transport protocol overthis interface may be General Packet Radio Services (GPRS) tunnelingprotocol-user plane (GTP-U). The S-GW 60 provides an S5 interface to apacket data node gateway (PDN GW) 70 which is adapted to establish an IPconnection to a public IP network 80.

The MME 50 manages mobility, UE identities and security parameters. Thecore network functionalities of the MME 50 include at least some ofnon-access stratum (NAS) signaling and related security, inter corenetwork node signaling for mobility between access network, idle mode UEtracking and reachability (including control and execution of pagingretransmission), roaming, authentication, and bearer managementfunctions including dedicated bearer establishment.

The S-GW 60 is the node that terminates the interface towards thewireless access network (e.g. EUTRAN). For each UE 10 associated with anevolved packet service, at a given point of time, there may be onesingle S-GW. The core network functionalities of the S-GW 60 include atleast some of local mobility anchor point for inter-eNB handover,mobility anchoring for inter-3GPP mobility, EUTRAN idle mode downlinkpacket buffering and initiation of network triggered service requestprocedure, lawful interception, and packet routing and forwarding.

Furthermore, the PDN GW 70 is the node that terminates the SGi interfacetowards the packet data network (PDN), e.g. the Public IP network 80. Ifthe UE 10 is accessing multiple PDNs, there may be more than one PDN GWfor that UE 10. The core network functionalities of the PDN GW 70include at least some of mobility anchor for mobility between 3GPPaccess systems and non-3GPP access systems (which is sometimes referredto as the system architecture evolution (SAE) anchor function), policyenforcement, per-user based packet filtering (by e.g. deep packetinspection), charging support, lawful Interception, UE IP addressallocation, and packet screening.

According to the architecture of FIG. 1, standard functionality, such asfor example, NNSF and multi-CN-node connectivity is located outside theHeNB 20 and is now centralized in the HeNB gateway 40 between the HeNB20 and the core network (e.g. EPC (Evolved Packet Core)).

The following simplifications can be introduced in the proposed HeNBarchitecture, in favour of the proposed introduction of the HeNB gateway20.

As to its control plane functionality, the connectivity of the HeNB 20can be restricted to connect (at least logically) to a single corenetwork node, i.e. the pooling property of the control plane of the corenetwork should be transparent to the HeNB 20. This eases configurationsetup of the HeNB 20 and handling of connectivity towards the corenetwork within the HeNB 20. as an example, the HeNB 20 may connect tothe core network via a single SCTP association containing a single SCTPstream and a single IP address (i.e. no IP multihoming). This isdifferent to the S1-C property of the macro eNB 40, where common S1APprocedures are handled via a separated SCTP stream and dedicated S1APprocedures via a few SCTP streams.

It is noted that a single SCTP stream is usually not used to map 1:1 toa UE dedicated connection, IDs generated by the application part shallbe used to establish UE dedicated S1 signalling relations between UEdedicated contexts located in the MME (pool) 50 and the eNB 30.

Consequently, the HeNB 20 connects control-plane-wise only to a singlenetwork node of the core network and does not contain any NNSF (S1-flex)function. This function is now located in the HeNB gateway 40.

As to its user plane functionality, the HeNB 20 connects to the corenetwork via a single IP address. Handling of tunnel endpoint identifiers(TEIDs) can take place without specific requirements for uplink (UL)traffic (e.g. the TEED can be allocated by the EPC's S-GWs 321 to 323).

Furthermore, the HeNB 20 can be logically connected to the same MME 50,which serves the macro layer as well. By this measure, unnecessarymobility actions (e.g. inter-MME pool handover (HO) at the HeNB 120 orHO scenarios at the macro eNB 30) of the HeNB gateway 40 might berestricted to a certain geographical area, corresponding to an MME(pool) area.

The HeNB gateway 40 can be adapted to relate the location of the HeNB 20with the MME 50 serving the eNB 30 that provides the macro cell underwhich the respective HeNB is located. In this manner it avoids inter-MMEhandovers (HOs).

As to its control plane functionality, the HeNB gateway 40 holdsinformation about connectivity to various operators' core networks (e.g.MME pools). In order to enable S1-flex connectivity for the HeNB 20,without deploying and configuring the HeNB 20 with this functionality,the HeNB gateway 40 may provide a 1:n relay functionality. This can bebased on the provision of global node-ID's on S1AP protocol level.Hence, the HeNB gateway 40 acts—in principle—similar to a (macro) eNBtowards the core network, i.e., it performs automatic registrationtowards (a pool of) MME entities. A specific tracking area identity oridentification (which may consist of a tracking area code (TAC) out of arange of specific TACs, indicating a closed subscriber group (CSG)and/or a home access) indicated during an automatic setup could indicatethe specific property of the HeNB gateway 40.

The HeNB gateway 40 can be connected via several IP addresses (IPmultihoming) and at least several SCTP streams (on dedicated or commonsignalling). Connectivity between the HeNB 20 and the HeNB gateway 40can be established on demand and this might change dependent on theactivity of a HeNB or users choice. This dynamic connectivity-behaviour,which may be more dynamic than from the macro eNB 30 can be transparentto the core network.

Thus, the HeNB gateway 40 acts towards the HeNB 20 as a single corenetwork node, and towards the core network as a single eNB. As alreadymentioned, the HeNB gateway 40, acting as an eNB towards a core networknode might necessitate to itself at automatic S1 setup with a specificidentification, e.g. a tracking area with a specific tracking area code(a single specific one or out of a set of dedicated “home” Tracking AreaCodes). This information can be provided on the HeNB broadcast channel.

Additionally, the HeNB gateway 40 may hold (store) at least one mappingtable to translate the location information provided by the HeNB 20 toan MME-pool connectivity information, e.g., not only of the “owning”operator but also of foreign-operators. Thereby, the HeNB gateway 40 canrelay HO messages from/to the HeNB 20 to the macro eNB 30, withcorresponding translation of identifiers, if needed.

As to its user plane functionality, the HeNB gateway 40 translates (DL)tunnel endpoint identifiers (TEIDs) allocated by the HeNB 20, as theHeNB gateway 40 acts as a single node and the ranges selected by theHeNB 20 may overlap (depending on implementation specifics). Anotheralternative could be to coordinate/control TEID assignment by the corenetwork, and signal towards the HeNB 20 the range of (DL) TEIDs it isallowed to allocate at setup.

FIG. 2 shows a schematic block diagram of a HeNB 10 and a HeNB gateway42 according to various embodiments.

The HeNB 20 comprises a NodeB processing unit (NBPU) 102 for performingNodeB-related signal and control processing with the restrictionsaccording to the embodiments described herein. The NBPU 102 may beimplemented as a software controlled central processing unit (CPU) orany other processor device. Furthermore, the HeNB 20 comprises asingle-connectivity unit (SC) 104 which is controlled by the NBPU 102and which is configured to restrict the connectivity of the HeNB 20 to asingle core network connection towards the HeNB gateway 42, which can beselected from a group of core network addresses of a pool of HeNBgateway devices, as explained later in more detail. The SC 104 may beimplemented as a subroutine which controls the NBPU 102 or as a separatesoftware-controlled CPU or any other processor device.

Furthermore, according to FIG. 2, a HeNB gateway 42 comprises a gatewayprocessing unit (GWPU) 202 for performing the above mentioned multi-noderelated signal and control processing extracted from conventional eNBs.The GWPU 202 may be implemented as a software controlled centralprocessing unit (CPU) or any other processor device. Furthermore, theHeNB gateway 42 comprises a multi-connectivity unit (MC) 204 which iscontrolled by the GWPU 202 and which is configured to provide the abovementioned 1:n relay functionality. Mapping of addresses, locations, orIDs can be achieved by a memory or look-up table (LUT) (not shown) whichstores corresponding mapping table(s). The MC 204 may be implemented asa subroutine which controls the GWPU 202 or as a separatesoftware-controlled CPU or any other processor device.

Additionally, the HeNB gateway 42 according to FIG. 2 comprises acollocated de-centralized core network component, unit, or functionality205 which enables de-centralization of core network (e.g. EPC)functionalities, so that the HeNB gateway 42 can also be used forserving macro eNBs or any type of access device within the local areaserved by the HeNB gateway 42.

In the exemplary following embodiments, a few possible architectureoptions achievable for LBO in the HeNB gateway are described inconnection with first to sixth embodiments.

FIG. 3 shows a schematic network architecture with a HeNB gatewaysupport incorporating several gateway functionalities according to afirst embodiment, where the HeNB GW 42 also incorporates a S-GWfunctionality and a PDN GW functionality in its core networkfunctionality 205 of FIG. 2. In this architecture the U-plane terminatesat the HeNB GW 42, so that bearers can be established with the HeNB GW42 without the need of terminating at the centralized EPC 90, and an LBOfunctionality to the public IP network 80 can be achieved at the HeNB GW42. On top of the LBO for Internet traffic a further advantage is thattraffic exchanged by UEs served within the HeNB GW domain can be routedwithout involving the central EPC, i.e. user plane (U-plane) trafficroutes within a HeNB GW domain will go from one peer UE to the otherpeer UE passing through the HeNB GW as shown in FIG. 3. In thearchitecture shown in FIG. 3, the control plane (C-plane) signalling isstill forwarded to the MME 50 in the centralized EPC 90. This allows toreduce the complexity of the HeNB GW 42, which is important due to therelatively high number of HeNB GWs the operators will have to deploy ifvery high volumes of HeNBs need to be achieved. The U-plane and theC-plane are decoupled from each other, the first terminating at the HeNBGW 42 and the latter terminating at the EPC 90. Thus, in FIG. 4, a peerto peer traffic route between UEs 12, 14 in the same HeNB GW domain isachievable without involving the EPC 90.

FIG. 4 shows a schematic network architecture with a HeNB gatewaysupport incorporating several gateway functionalities according to asecond embodiment. In this alternative architecture, a HeNB GW 44 isprovided which also includes an MME functionality in its core networkfunctionality. In this architecture the U-plane and the C-plane for UEsconnected to base stations within the HeNB GW pool terminate locally atthe HeNB GW 44. This enables a more synchronized and easy to manageprocedure for bearer monitoring and C- and U-plane traffic mapping intoradio bearers.

It needs to be mentioned that the MME functionality in the HeNB GW 44can be part of a pool. Such a pool could consist of MMEs local to theHeNB GW 44, i.e. either stand alone MMEs or MMEs incorporated in otherHeNB GWs which are local to the concerned HeNB GW 44. It is also notedthat the MME functionality incorporated in the HeNB GW 44 can beinvolved in the establishment of S1-MME interfaces with macro eNBs (e.g.macro eNB 30) in the local area and in the establishment of S1-MME withHeNB GWs that are either co-located with the MME functionality or thatare in its same local area. In other words, the MME functionalityco-located with the HeNB GW 44 does not establish a direct S1-MMEinterface with the HeNBs in the local area. The HeNB 20 may onlyestablish a simplified S1 interface with the HeNB GW 44. In FIG. 4, thepeer to peer traffic route between UEs 12, 14 in the same HeNB GW domainis achievable without involving the EPC 90.

FIG. 5 shows a schematic network architecture with a HeNB gatewaysupport incorporating a single PDN gateway functionality according to athird embodiment, where a HeNB GW 46 only includes a PDN GWfunctionality in its core network functionality. The solution envisagedin this scenario implies the termination of U-plane bearers for Internettraffic transport at the HeNB GW 46, so that the S-GW 60 is not involvedin the establishment of U-plane bearers. This can be achieved e.g. byenabling a default bearer for Internet traffic with fixed quality ofservice (QoS) and that is terminated at the HeNB GW 46. In this way LBOfor Internet traffic could happen at the HeNB GW 46 without forcingcollocation of an S-GW functionality in it. This would make the HeNB GW46 more cost effective, still improving the cost per bit of informationtraveling across the centralized EPC 90.

FIG. 6 shows a schematic network architecture with a HeNB gatewaysupport incorporating a C-plane anchor functionality according to afourth embodiment, where the core network functionality of a HeNB GW 48only includes C-plane anchor functionalities (e.g. address translation,binding etc.) for HeNBs 20 (or pico, micro eNBs) with integrated PDN GWfunctionality for providing direct LBO to a private local area network(LAN) 100, e.g., a home LAN, a corporate LAN, a campus or any type ofintranet. The anchor functionality The solution envisaged in thisscenario implies the termination of the U-plane bearers for localintranet level peering and Internet access with “native IP” traffictransport at the HeNB 20. Even the UE 10 will see this as a normal 3GPPcompliant PDN connectivity associated with an access point name (APN)and related bearer(s). In this way there is no need to place theoperator owned HeNB GW 48 in the private premises without impacting thepossibility for the operator to manage the HeNBs 10 and fully controlthe consumed LBO services. Also the LBO traffic on the U-plane is keptwithin the local intranet e.g. safely behind the firewall.

In all the architecture scenarios described in connection with the abovefirst to fourth embodiments, the HeNB GW constitutes a single point offailure. A solution is needed in order to provide service continuity tousers in case of HeNB GW failure. A solution to this problem wouldconsist of configuring each HeNB with a pool of HeNB GWs, so that incase of primary HeNB GW failure the HeNBs can randomly pick one of thesecondary HeNB GWs configured, hence distributing the load morehomogeneously across secondary HeNB GWs. Further, before connecting to asecondary HeNB GW, signalling messages could be exchanged between theHeNB and the secondary HeNB GW, in order to determine what the currentload on the HeNB GW is, what the load the HeNB will generate (in termsof traffic) is and whether connection to the secondary GW is opportuneand affordable.

FIG. 7 shows a schematic processing and signaling diagram of a HeNBgateway reselection procedure according to a fifth embodiment, where theHeNB 20 randomly tries to connect to one of a plurality of secondaryHeNB GWs 43-1 to 43-n in his list and in order to do so it communicatesthe overall traffic load (uplink (UL) and/or downlink (DL)) experiencedwithin a past time window. A selected secondary HeNB GW will first ofall evaluate if it can sustain an extra S1-simplified connection andthen it will assess if it is able to sustain the overall trafficobtained by adding the current traffic load with the traffic loadcommunicated by the HeNB 20. If these two criteria are satisfied, theconnection will be established, otherwise connection will be rejectedand the HeNB 20 will try to connect to a different HeNB GW in thepreconfigured pool of secondary GWs 43-1 to 43-n.

In the exemplary scenario of FIG. 7, if a primary NeNB GW failurehappens, this is detected at the HeNB 20 (step 1). Then, traffic loadsustained in past prefixed time window is measured (step 2) and signaledto a selected or default first secondary NeNB GW1 43-1, evaluates instep 3 the overall traffic in case of a HeNB connection acceptance. Itis assumed in the exemplary scenario that the first secondary HeNB GW143-1 rejects the connection in step 4. Then, in step 5, the traffic loadsustained in the past prefixed time window is signaled to a secondsecondary HeNB GW2 43-2 which also evaluates overall traffic in case ofHeNB connection acceptance (step 6). It is now assumed that theconnection is accepted by the second secondary HeNB GW2 43-2, andconnection acceptance is signaled to the HeNB 20 in step 7, so that theconnection can be established via the second secondary HeNB GW2 43-2.

FIG. 8 shows a schematic block diagram of an alternative software-basedimplementation according to a sixth embodiment. The requiredfunctionalities can be implemented in any network entity (which may beprovided in the HeNB 20 or the above HeNB gateways 41, 42, 43, 44, 46,or 48) with a processing unit 410, which may be any processor orcomputer device with a control unit which performs control based onsoftware routines of a control program stored in a memory 412. Thecontrol program may also be stored separately on a computer-readablemedium. Program code instructions are fetched from the memory 412 andare loaded to the control unit of the processing unit 410 in order toperform the processing steps of the above device-specificfunctionalities which may be implemented as the above mentioned softwareroutines. The processing steps may be performed on the basis of inputdata DI and may generate output data DO. In case of the HeNB 20, theinput data DI may correspond to a connection request for triggering aconnection set-up, and the output data DO may correspond to a selectedgateway address. In case of the HeNB gateway 41, 42, 43, 44, 46, or 48,the input data DI may correspond to request for LBO or anotherdecentralized core network related procedure, and the output data DO maycorrespond to the signaling required for implementing the requested corenetwork related functionality.

Consequently, the above embodiments of the HeNB and HeNB gateway may beimplemented as a computer program product comprising code means forgenerating each individual step of the signaling procedures for therespective entity when run on a computer device or data processor of therespective entity at the HeNB 20 or the HeNB gateway 41, 42, 43, 44, 46,or 48 or any corresponding network entity.

The implementation of the above embodiments thus comprisesdecentralization of at least a part of the EPC functionalities andco-locating it with the HeNB GW. This is a new approach to decentralizedarchitectures because the decentralization of EPC and the HeNBarchitectures have so far been seen as two separate problems andsolutions addressing both issues at the same time have not yet beensought. Moreover, the advantage of the solutions presented above is thatthe enhanced HeNB GW containing elements of the EPC is no more used forserving only HeNBs, but it is used also for serving macro eNBs or anytype of eNB within the local area served by the HeNB GW.

Other clear advantages of the above embodiments are that they allowlocal break-out of bulk internet traffic at a point local to the basestations (e.g. HeNB or eNB), i.e. it allows Internet traffic not to berouted through the central EPC, hence reducing the cost per bit ofinformation delivered to/from the user.

Also, the fifth embodiment may serve to overcome single point of failureproblems concerning failures of HeNB GWs (independently of the EPCfunctionalities collocated with it). A homogeneous distribution of theHeNBs affected by a HeNB GW failure across a predefined pool ofneighbour HeNB GWs is allowed.

In summary, a method, apparatus, and computer program product have beendescribed, wherein a connection to a core network is established via awireless access device and a gateway device. Connectivity of thewireless access device is restricted to a pre-defined group of corenetwork address of a pool of gateway devices with multi-nodeconnectivity to the core network, and a single address is selected toestablish the connection to a one of the gateway devices. The gatewaydevice is provided with a relay function for mapping a single inputaddress to a plurality of core network addresses based on a locationinformation of the wireless access device and with at least oneco-located decentralized core network functionality.

It is apparent that the invention can easily be extended to any serviceand network environment and is not restricted to the LTE technology areaand in particular not to home eNBs. The proposed embodiments can beimplemented in connection with any base station with limited coverage(usually employed for indoor coverage and improved user experience inthe home area) deployed in a wireless network. The embodiments may thusvary within the scope of the attached claims.

What is claimed is:
 1. A method of providing network access, the methodcomprising establishing a connection to a core network via a wirelessaccess device, wherein a user plane of the connection is terminated atthe wireless access device and/or a gateway device connected to the corenetwork without involving the core network, and a control plane of theconnection is restricted to connect to the core network.
 2. A method ofproviding network access, the method comprising: using a gateway devicefor establishing a connection from a wireless access device to a corenetwork; providing the gateway device with a relay function for mappinga single address of the wireless access device to a plurality of corenetwork addresses of a pool of gateway devices connected to the corenetwork; decentralizing at least one core network functionality andco-locating it with the gateway device; and terminating at least one ofa user plane and a control plane of the connection, at the wirelessaccess device and/or the gateway device using the at least one corenetwork functionality.
 3. The method according to claim 1, furthercomprising establishing the user-plane connection to the gateway devicevia a single Internet Protocol address.
 4. The method according to claim2, further comprising connecting the gateway device to the core networkvia one or more Internet Protocol addresses and one or more transmissionprotocol streams.
 5. The method according to claim 1, further comprisingestablishing the control-plane connection to the gateway device via asingle transmission protocol association containing a singletransmission protocol stream and a single Internet Protocol address. 6.The method according to claim 1, further comprising performing automaticset-up of the gateway device with a pre-defined identification.
 7. Themethod according to claim 6, wherein the predefined identificationcomprises a tracking area with at least one dedicated tracking areacode.
 8. The method according to claim 2, wherein the at least one corenetwork functionality comprises at least one of a serving gatewayfunctionality, a packet data network gateway functionality, a mobilitymanagement functionality, and a control plane anchor function, so thatat least one of the user plane and the control plane of the connectionis terminated at the wireless access device and/or the gateway device.9. The method according to claim 8, wherein the mobility managementfunctionality is part of a pool of mobility management entities local tothe gateway device.
 10. The method according to claim 2, furthercomprising using the at least one core network functionality to providelocal routing without passing a centralized gateway device at the corenetwork.
 11. An apparatus for providing access to a core network, theapparatus comprising connecting means for establishing a connection tothe core network from the apparatus, wherein a user plane of theconnection is terminated at one of a pool of gateway devices connectedto the core network without involving the core network, and a controlplane of the connection is restricted to connect to the core network.12. The apparatus according to claim 11, wherein the connecting means isadapted to establish the control-plane connection to the one of thegateway devices via a single transmission protocol associationcontaining a single transmission protocol stream and a single InternetProtocol address.
 13. The apparatus according to claim 11, wherein theconnecting means is adapted to establish the user-plane connection tothe one of the gateway devices via a single Internet Protocol address.14. A wireless access device comprising an apparatus according to claim11.
 15. An apparatus for establishing a connection from a wirelessaccess device to a core network, the apparatus comprising: relay meansfor mapping a single address of the wireless access device to aplurality of core network addresses; and at least one co-locateddecentralized core network functionality, wherein a user plane of theconnection is terminated at the wireless access device using the atleast one co-located decentralized core network functionality.
 16. Theapparatus according to claim 15, wherein the relay means is configuredto provide a connection to the core network via one or more InternetProtocol addresses and one or more transmission protocol streams. 17.The apparatus according to claim 15, wherein the relay means provides alogical signaling interface between the wireless access device and otherwireless access devices or macro access devices which provide macrocells.
 18. The apparatus according to claim 15, wherein the at least onecore network functionality comprises at least one of a serving gatewayfunctionality, a packet data network gateway functionality, a mobilitymanagement functionality, and a control plane anchor function, so thatat least one of the user plane and the control plane of the connectionis terminated at the gateway device.
 19. The apparatus according toclaim 15, wherein the apparatus is configured to use the at least onecore network functionality to provide local routing without passing acentralized gateway device at the core network.
 20. A gateway devicecomprising an apparatus according to claim 15.